DAIRY FARMING — DAIRYING. 575 



existence of some mechanism otlier than tlie formation and deposition of an 

 egg wliich controls the extrusion of the egg. It is said that laying hens often 

 visit the nest at the proper day and hour, but fail to lay. Such hens usually 

 lay the day previous and the day after in regular routine, though at times they 

 may pay two or more such nonproductive visits in succession. 



The amount of carbon dioxid thrown off by eggs during the incubating 

 process, H. Atwood and C. E. Weakley, Jr. {Jour. Amcr. Assoc. Instr. and 

 In-vest. Poultry Hush., 1 (1915), No. 4, pp. 26-28). — Work is reported from the 

 West Virginia Station in which the carbon dioxid thrown off by nine eggs 

 from three hens during incubation was determined. 



It was found that as the incubating process goes on the carbon dioxid thrown 

 off increases very rapidly. The loss of carbon dioxid during the last five days 

 of incubation was about five-eighths of the total loss of carbon dioxid, twice as 

 much as that given off in the third five days, ten times as much as that in the 

 second five days, and almost fifty times as much as that in the first five days. 

 In an incubator this carbon dioxid must be removed or at least kept below a 

 certain maximum, which some investigators (E. S. R., 31, p. 172) have found to 

 be 150 parts in 10,000. If this maximum is not to be exceeded, 100 fertile eggs 

 will require 1G5 cu. ft. of fresh air to be passed over and around them on the 

 twentieth day to keep the embryos from smothering. 



A considerable excess of air was used in this test with no ill effect. 



Peacock-guinea fowl hybrids, D. Brentana (Mod. Zooiatro, Parte Sci., 

 25 (1914), No. 11, pp. 1001-1009, figs. 2; aJjs. in Internat. Inst. Agr. [Rome}, Mo. 

 Bui. Agr. Intel, and Plant Diseases, 6 (1915), No. 2, pp. 280, 281).— An account 

 is given of the hybridization between two guinea fowl hens and a peacock. 



The hybrids resembled the peacock more in their general slender form, 

 especially in the head and neck, although there was a noticeable absence of all 

 the characteristic appendages of the head and the train was much reduced. 

 The plumage exhibited sti-iping, which is to be considered as the primitive 

 type. It was of a dark fawn with black stripes in the lower part of the neck, 

 becoming paler fawn with black specks in the region of the thorax, abdomen, 

 and flanks. 



Bibliography [of poultry literature] (Jour. Anier. Assoc. Instr. and Invest. 

 Poultry Hush., 1 (1914), No. 2, pp. 5-7).— A bibliography of poultry literature 

 published between July, 1913, and July, 1914. 



DAIRY FARMING— DAIRYING. 



The value of barley for cows fed alfalfa, G. H. True, F. W. Woll, and E. C. 

 Voorhies (California Sta. Bui. 256 (1915), pp. 423-445, flgs. 7).— Two lots of 

 seven cows each, as nearly alike as possible with reference to breed, age, 

 weight, and production, were fed during three periods of three weeks each by 

 the reversal method, one lot receiving 30 lbs. per day of green alfalfa and 

 alfalfa hay ad libitum, while the other lot received in addition approximately 

 1 lb. of barley to every 5 lbs. of milk produced by the cow. 



During the alfalfa-barley periods the cows consumed an average of 210 lbs. 

 of green alfalfa, 141 lbs. of alfalfa hay, and 42 lbs. of barley per head per 

 week, and produced 183.3 lbs. of 3.6 iier cent milk, or 6.65 lbs. of milk fat ; dur- 

 ing the alfalfa periods, 210 lbs. of green alfalfa and 153 lbs. of alfalfa hay, and 

 produced 157.6 lbs. of 3.7 per cent milk, or 5.87 lbs. of milk fat. 



Comparing the net increase in the cost of the rations incurred by feeding 

 barley with the increased value of production, a profit of $4.78 was secured as 

 a result of adding barley to the alfalfa ration, on the basis of selling milk at 

 16 cts. per gallon and including the value of the gain in weight by the cows 



